ONE of the officers who shot Tube blunder
man Jean Charles de Menezes is to train new British sky marshals.

The armed cop, in his 30s, has been picked because
top brass say he has "proven ability to act swiftly and decisively"
in emergencies.

Officers from his unit will be secretly placed on some
jets feared to be at particular risk on routes from the UK to America.

Ministers first raised the idea of the undercover armed
units in 2002 following US pressure. But they refuse to reveal if the teams
are already being deployed.

The decision to have the detective involved in last
year's tragedy at Stockwell, South London, as their instructor will spark
fury in some quarters.

No policemen will face charges over Mr de Menezes's
death.

But security services insiders insist the officer -
part of Scotland Yard's elite CO19 gun squad - is the best man for the job.

One senior source said: "The shooting was a terrible
mistake, but it was made in response to a genuine fear that this man was
a terrorist about to blow up innocent people.

"We need the best to counter the very real threat
posed by international terrorism.

"Sky marshals have to act quickly and decisively
in any situation.

"They have to be ruthless in bringing down potential
terrorists before they can bring down an aircraft."

All UK police forces have been told to send firearms
officers for the eight-week course because of the heightened terror alert.

The teams will attend the Metropolitan Police's Specialist
Training Centre in Gravesend, Kent -one of the best in the world.

They will learn how to tackle hijackers and use firearms
in mid-air.

Sky marshals will be issued with Sig Sauer 9mm pistols,
with special bullets which do not ricochet and damage the aircraft's fuselage.

Officers will also be taught how to man cockpit controls
when the crew have been killed or injured.

Following 9/11, Washington put pressure on European
governments to have at least three sky marshals on US-bound flights. Many,
notably Sweden, Portugal and Denmark, fiercely opposed the plan, as did
the British Airline Pilots' Association.

The UK is thought to have started training undercover
air guards in 2002.

In 2004, following speculation that the Government
had secretly axed the plan, the Department of Transport said: "We could
deploy sky marshals if we wanted to. It's just that we don't talk about
it."

They have been in use on US planes for more than 40
years.

The programme was set up in 1961 by US president John
F Kennedy amid growing fears over hijacks.

Ronald Reagan boosted their numbers after a Lebanese
gun gang seized a TWA jet in Athens in 1985, shot a US passenger and hurled
his body on to the tarmac.

American marshals take a seven-week course at a training
academy in Artesia, New Mexico. They then have four weeks at a specialist
air marshal training centre in Atlantic City, New Jersey.

In December last year, sky marshals killed for the
first time when a mentally disturbed airline passenger who pretended that
he had a bomb in his bag was shot at Miami airport.

Brazilian Mr Menezes, 27, was gunned down on July 22
last year after officers mistook him for a suicide bomber.

The Crown Prosecution Service says there is "insufficient
evidence" to prosecute any individual. But the Met Police will be charged
under health and safety laws. An Independent Police Complaints Commission
report given to the CPS in January, but not yet made public, is said to
be highly critical of the police operation.